The present invention relates generally to roadway construction and more particularly to techniques for avoiding crumbling or deterioration of the structural edges of a roadway joint assembly. More specifically, the invention is especially adaptable for use in roadway structures wherein joint assemblies having resilient characteristics are utilized.
As is generally known, one of the most troublesome problems related to concrete structures upon which vehicular traffic must pass is the wear and deterioration that occurs to the edges of pavement or similar material, particularly at joints which must be formed between two adjacent concrete walls or slabs which form the roadway structure.
In order to overcome problems of this type, many attempts have been made to provide protective devices for different parts of the roadway. Such protective devices may involve, for example, angular iron members, steel ribs and the like.
However, all of the metallic protectors which are in use today give rise to great inconvenience for several reasons. First of all, it is relatively difficult to achieve a good metal-to-concrete connection primarily due to the rather difficult conditions created by different thermal expansion coefficients. As a result, the attachment of such metallic protectors will generally be accomplished by the utilization of anchorage devices which must be imbedded into the concrete and which must be welded to metallic protective members.
As will be evident, significant stresses will arise in roadway structures whereby different parts of the roadway will move relative to other parts because of the different stresses and because of varying thermal characteristics. The stresses which occur because of traffic load will usually be concentrated at the metallic anchorage devices thereby causing them to become loosened after a relatively short period of time. This and other problems which arise in structures of this type will require frequent road maintenance procedures.
The present invention is directed toward providing an improved protective system for roadbed joints of the type described above. The advantage of the present invention resides in the fact that continuous structural protection may be built-in at the edge of the concrete slab of the roadway without requiring utilization of metallic anchorages. Protection of the type afforded by the present invention enables high performance anti-abrasive edge structures to be provided which may be totally bonded to the concrete of the roadway slab and which will present a thermal expansion coefficient equivalent to the thermal expansion coefficient of the concrete itself.
Of particular importance is the fact that the arrangement of the present invention permits the utilization of flexible joints, especially a joint of a particular type which gives rise to significant advantage.
The significant advantages of the invention involve the fact that the roadway joints utilizing the invention may be built at any time after the pouring of the concrete without depending upon accurate positioning of metallic protectors or anchors. The joint may be totally or partially repaired without destroying the nearby concrete and it will provide a continuous non-skid surface. The arrangement of the invention provides a joint which is totally capable of resisting oxidation, water penetration and which is also resistant to most solvents and chemicals. The invention permits the equal distribution of load of traffic over the joint system while avoiding stress concentration.